[nix-shell:~/dev/zig/build]$ ./zig build-exe ../src-self-hosted/ir.zig 
Code Generation [3498/4100] std.fmt.format...broken LLVM module found: Terminator found in the middle of a basic block!
label %EndIf35
Terminator found in the middle of a basic block!
label %EndIf37
Terminator found in the middle of a basic block!
label %EndIf39
Terminator found in the middle of a basic block!
label %EndIf44
Terminator found in the middle of a basic block!
label %EndIf50
Terminator found in the middle of a basic block!
label %EndIf52
Terminator found in the middle of a basic block!
label %EndIf58

This is a bug in the Zig compiler.
/home/andy/dev/zig/src-self-hosted/stage2.zig:37:5: 0xb6a50c in stage2_panic (zigstage2)
    @panic(ptr[0..len]);
    ^
/home/andy/dev/zig/src/util.cpp:20:17: 0xb29947 in zig_panic (/home/andy/dev/zig/src/util.cpp)
    stage2_panic("", 0);
                ^
/home/andy/dev/zig/src/codegen.cpp:8180:18: 0xa6d1e2 in do_code_gen (/home/andy/dev/zig/src/codegen.cpp)
        zig_panic("broken LLVM module found: %s\nThis is a bug in the Zig compiler.", error);
                 ^
/home/andy/dev/zig/src/codegen.cpp:10927:24: 0xa77e0a in codegen_build_and_link (/home/andy/dev/zig/src/codegen.cpp)
            do_code_gen(g);
                       ^
/home/andy/dev/zig/src/main.cpp:1671:39: 0xa4a34a in main0 (/home/andy/dev/zig/src/main.cpp)
                codegen_build_and_link(g);
                                      ^
/home/andy/dev/zig/src/main.cpp:1858:24: 0xa4ae74 in main (/home/andy/dev/zig/src/main.cpp)
    auto result = main0(argc, argv);
                       ^
Aborted (core dumped)